The final release of AS/NZS3760:2003 certainly caused some buzz around the net - not everything put up was quite fact and ultimately common sense prevailed to prevent WW3 erupting.
So what's new and caused the buzz : leakage testing!
The Committee considered that
leakage testing had some advantages in some situations and therefore made a
subtle change to the 2001 version by making it the first alternative in the
Standard where insulation testing is not practical..
For appliances which have a power
switch which requires that the item is actually connected to the power in order
to operate manual attempts to turn it on are unlikely to be successful, in these
special cases with the item turned on to operate the switch, an attempt to
undertake an insulation test (remembering the need to join the active and
neutral pins) is unlikely to be successful either. In these special
situations then, the only practical and sensible way to measure the Insulation
Resistance is to undertake a Leakage Test.
There is a new Time Frames for Testing now called TABLE 4
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Competent Person
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Addition of a New Test
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Inspection, Testing & Tagging
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PAT Testers
Guidelines for training of competent people - this has been made for NZ only. However, regardless of how these competent people are trained they do need to be competent and this does not mean holding some kind of Certificate or Licence. Competent means that they are sufficiently skilled to enable them to undertake the inspection and testing as required by the Standard on the equipment they need to inspect and test.
The Committee responsible for writing AS/NZS3760 has seen the need to replace the 500-volt insulation test with an alternative LEAKAGE TEST in some instances. The 500V insulation test is still allowed except where the equipment under test has internal switching which is only switched when the equipment is powered up. Sometimes deciding what type of switches an appliance has can be difficult so with this in mind if any doubt exists then a leakage test should be done.
The Leakage test is designed to ensure the whole of the appliance is safe not just a part of it.
Remembering that
Class II 
equipment relies solely on insulation for
safety i.e. has no protective earth connection - meaning the results of the
leakage test are very important.
Those companies needing to purchase replacement test equipment would be very wise to purchase the tester with a leakage facility, companies that do not wish to replace test equipment could measure leakage via a clip-on clamp meter capable of measuring milliamps.
For hire companies it is the the hire company that needs to ensure that the equipment meets the Standard at the time of hire - it becomes the users responsibility after the commencement of Hire.
Table 4 is to be used to ascertain the correct inspection and testing time intervals.
Table 4 requires the hire company to inspect prior to hire and that testing is done 3 monthly.
IMPORTANT the time taken to inspect equipment is usually far more than the time to test equipment. There are lots of PAT Testers (Portable Appliance Testers on the market that can test equipment properly in a matter of seconds and record results in the memory of the testers virtually instantly.
I know many hire companies will be still choosing to inspect and test prior to hire. This choice is obviously left up to the individual companies to make, but please bear in mind the little extra time compared to the increased risk.
Most general hire companies will be relatively happy with the present tag system or at least not too unhappy. However some specialist entertainment hirers have problems with tagging and keeping track of hundreds of leads etc. The new Standard makes allowances for this by allowing alternative options to tagging. This may include electronic tracing and results/details stored on RFID tags or similar. There are conditions placed on this i.e. test results must be available on site the next working day.
The latest draft of AS/NZS3760 also makes mention of the PAT Tester by name and an important addition here is also the notes that give details of the differences between the different earth testing i.e.
| 100mA | = continuity |
| 10Amp |
= routine testing |
| 25Amp or1.5 rated current of appliance |
= type test |
As discussed earlier there is a need to be able, where required, for test equipment to be able to do leakage testing. There are many PAT Testers on the market that will do load and leakage test and 250/500-volt insulation testing. Earth testing of 100MA, 10A and 25Amps as well as store results. Some PATs will also do 3-phase testing with the addition of an external clamp and still record results electronically.
If you need to purchase a new test equipment shop around and be wary of very cheap options. Ensure they will do at least a 10Amp and 100mA earth test as well as a leakage test.
There are testers that will meet all the above requirements and store results available with software for under $2000.
Risk Management
Introduced in this new edition of the Standard is the possibility of allocating the frequency of inspection/testing by undertaking, implementing and documenting a risk assessment.
Other Changes
There are many other minor text changes which are intended to give the reader greater clarity and understanding. If you have a specific query, concern or would like help with testing then please contact us.